About this replacement
Designed for Topcon devices. Compatible models include CS-100, CTS-3000, GPT-1000, GPT-1003, GPT-1004, GPT-102R, GPT-2000, GPT-3000, GPT3000W, GPT3100W, GPT3200, GRS-245NW. Replacement part numbers include 51730, BT-32Q, BT-52Q, BT-52QA, BT-G1, TBB-2, TBB-2R.