bathhouse entry ticket; bathing ticket
A ticket that grants admission to a public bathhouse or hot spring facility.
銭湯に入るには入浴券を買ってください。
Please buy a bathing ticket to enter the public bath.
この入浴券で温泉施設が利用できます。
You can use the hot spring facility with this bathing ticket.
Compound of 入浴 (にゅうよく, 'bathing') and 券 (けん, 'ticket').