SRB CORP - 20 Mar 2026 Form 4 Insider Report for SAFETY INSURANCE GROUP INC (SAFT)

Footnote F1

This Form 4 is being jointly filed by SRB Corporation, a Massachusetts corporation ("SRB"), and The Plymouth Rock Company Incorporated, a Massachusetts corporation ("PRC"), and each shall be deemed a Reporting Person. SRB is a direct, wholly-owned subsidiary of PRC and acts as investment manager to PRC and, in such capacity, may be deemed to have voting and dispositive power over the shares of Common Stock reported on this Form 4. SRB disclaims beneficial ownership of the shares of Common Stock reported on this Form 4, and this report shall not be deemed an admission that SRB is a beneficial owner of such shares for purposes of Section 16 or for any other purpose. (Continued in Footnote 2)

Footnote F2

The Reporting Persons are making this single joint filing because they may be deemed a "group" within the meaning of Section 13(d)(3) of the Securities Act of 1934, as amended. This joint filing shall not, however, be deemed an affirmation that a group exists among the Reporting Persons for the purposes of the Securities Exchange Act of 1934 or for any other purpose and each Reporting Person expressly disclaims beneficial ownership of any securities beneficially owned by any other person.

Footnote F3

PRC holds 4,120 of the shares of Common Stock reported on this Form 4. The following subsidiaries of PRC hold in the aggregate 772,856 shares of the Common Stock reported on this Form 4: Plymouth Rock Security Corporation, a Massachusetts security corporation ("PRSC"); Plymouth Rock Assurance Corporation, a Massachusetts corporation ("PRAC"); Plymouth Rock Assurance Preferred Corporation, a New York corporation ("PRAPC"); Plymouth Rock Assurance Corporation of New York, a New York corporation ("PRACNY"); Pilgrim Insurance Company, a Massachusetts corporation ("Pilgrim"); Plymouth Rock Home Assurance Corporation, a Massachusetts corporation ("PRHAC"); Bunker Hill Insurance Casualty Company, a Massachusetts corporation ("BHICC"); Bunker Hill Preferred Insurance Company, a Massachusetts corporation ("BHPREFIC"); Bunker Hill Property Insurance Company, a Massachusetts corporation ("BHPIC"); (Continued in Footnote 4)

Footnote F4

and Bunker Hill Insurance Company, a Massachusetts corporation ("BHIC"). PRSC, PRAC, and PRHAC are direct wholly-owned subsidiaries of PRC. PRAPC and PRACNY are direct wholly-owned subsidiaries of PRAC. Pilgrim is a direct wholly-owned subsidiary of SRB. BHICC, BHPREFIC, BHPIC, and BHIC are direct wholly-owned subsidiaries of PRHAC. Palisades Safety and Insurance Association, a New Jersey reciprocal insurance exchange ("PSIA"), is managed by a subsidiary of PRC. PSIA and the following subsidiaries of PSIA hold in the aggregate 1,017,679 shares of the Common Stock reported on this Form 4: High Point Safety and Insurance Company, a New Jersey corporation ("HPSIC"); High Point Property and Casualty Insurance Company, a New Jersey corporation ("HPPCIC"); High Point Preferred Insurance Company, a New Jersey corporation ("HPPIC"); Palisades Insurance Company, a New Jersey corporation ("PICNJ"); (Continued in Footnote 5)

Footnote F5

Twin Lights Insurance Company, a New Jersey corporation ("TLIC"); and Teachers Auto Insurance Company of New Jersey, a New Jersey corporation ("TAIC"). HPSIC, HPPIC, TLIC, and TAIC are direct wholly-owned subsidiaries of HPPCIC, which is a direct wholly-owned subsidiary of PSIA, as is PICNJ. PRC disclaims beneficial ownership of the shares of Common Stock reported on this Form 4 except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that PRC is a beneficial owner of such shares for purposes of Section 16 or for any other purpose.