E-Collar Technologies 33" Biothane Collar with Buckle and BungeeAvailable in 3 4" and 1" Bungee loop for expansion Available in multiple colors Genuine E Collar Technologies [split] Genuine replacement biothane collars from E Collar Technologies. These collars include a bungee loop to allow for expansion during heavy breathing or barking. These collars are 33" long and can be trimmed to length. Available in 3 4" and 1" widths. RX 050, RX 070 and RX 090 receivers accept 3 4" collars. RX 120 receivers accept 1"